This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 0 |
| 2 | 0 |
| 3 | 2 |
| 4 | 5 |
| 5 | 30 |
| 6 | 163 |
| 7 | 1172 |
| 8 | 9349 |
| 9 | 84208 |
| 10 | 842149 |
| 11 | 9266416 |
| 12 | 111220875 |
| 13 | 1446134218 |
| 14 | 20248984181 |
| 15 | 303774206310 |
| 16 | 4860923772369 |
| 17 | 82643503648838 |
| 18 | 1487703851220935 |
| 19 | 28268359232622252 |
| 20 | 565401755237435337 |
| 21 | 11874072125853230504 |
| 22 | 261241878854832755345 |
| 23 | 6008813069875360106928 |
| 24 | 144216837237680799509479 |
| 25 | 3605539586383814138649074 |